Packing gland



E. 1.. WHEELER 3,350,106

PACKING GLAND Oct. 31, 1967 Filed Dec- 21, 1964 INVENTOR. EDGAR L.WHEELER 6mm: 6 dfi u a/ ATTORNEYS.

United States Patent 3,350,106 PACKING GLAND Edgar L. Wheeler, 5636Blanco Ave, Woodland Hills, Calif. 91364 Filed Dec. 21, 1964, Ser. No.419,859 6 Claims. (Cl. 277-59) This invention relates generally topacking glands and more particularly to a novel packing gland forpassing a rotatable member into an enclosure under a pressure differentfrom the exterior pressure.

In both commercial and research chemical laboratories it is oftentimesdesirable to be able to mix or stir the contents of a flask or otherenclosure while maintaining the pressure of ingredients in the enclosureat values to which they would normally be subject were the flask sealedat all times. For example, there are situations in which a relativelyhigh vacuum is maintained in a flask and it is normally difficult tostir or mix the ingredients in the flask without losing some of thevacuum as a consequence of leakage when a stirring means is introducedand operated. In other instances, the ingredients may be under apressure considerably greater than the ambient pressure and again itbecomes difiicult to stir the contents without a loss of this higherinterior pressure.

With the foregoing in mind, it is accordingly a primary object of thepresent invention to provide a novel packing gland structure designed,in its preferred embodiment, to be received within the neck of a flaskand through which a stirring means is passed to enable stirring of thecontents within the flask while maintaining the pressure difference thatwould exist between the interior pressure of the flask and the exteriorwere the flask at all times completely hermetically sealed.

More particularly, it is an object to provide a packing gland forpassing a rotatable member such as a suitable stirring means into aflask to enable stirring of the contents of the flask while thesecontents are under a relatively high vacuum without any leakage ofexterior gases into the flask.

Another object is to provide a packing gland meeting the foregoingobject which will also prevent a loss of a greater interior pressure inthe flask to the exterior dur ing a stirring operation.

A particularly important object is to provide a novel packing gland inwhich a scaling is effected about a ro tatable member even though themember may be rotated at high speed, between an interior pressure withinan enclosure and an exterior pressure wherein the effectiveness of thesealing increases in proportion to the pressure difference existing.

Briefly, these and many other objects and advantages of this inventionare attained by providing a housing structure for connection to a flaskor other enclosure. In the preferred embodiment of the invention, thishousing structure defines an interior chamber and includes inlet andoutlet bores having first ends extending into the chamber and secondends communicating respectively with the interior of the enclosure andthe exterior thereof. A stirring means is introduced through thetwobores to extend from the exterior to the interior of the enclosure.

Within the chamber there are provided first and second resilient sleevestructures surrounding the first ends of the bores and extending alongportions of the stirring means given distances and thence engaging theperipheries of these portions in sealing relationship. The chamber itself is filled with an incompressible fluid, preferably in the form oflubricating oil, which serves to communicate pressure to which theinterior of the first sleeve is sub ject to the exterior of the secondsleeve thereby main taining the second sleeve in tight sealingrelationship with the rotatable member when the pressure within theenclosure is greater than the exterior pressure. Similarly, thisincompressible fluid will transmit pressure to which the interior of thesecond sleeve is subject to the exterior of the first sleeve to maintainthe first sleeve in tight sealing relationship with the stirring meanswhen the exterior pressure is greater than the interior pressure withinthe enclosure.

The incompressible fluid in the form of an oil as stated serves theadditional function of lubricating the engaging areas of the sleeveswith the stirring means.

A better understanding of the invention will be had by now referring tothe preferred embodiment thereof as illustrated in the accompanyingdrawings, in which:

FIGURE 1 is a perspective view of a flask incorporating the packinggland of this invention; 7

FIGURE 2 is an enlarged view of the packing gland partly incross-section taken in the direction of the ar rows 2-2 of FIGURE 1; and

FIGURE 3 is a further enlarged fragmentary view part ly in cross-sectionof a portion of the structure illustrated in FIGURE 2.

Referring first to FIGURE 1 there is shown a flask 10 having an upperneck opening 11. Positioned above the opening 11 is a housing 12terminating at its lower end in a shaped plug portion 13 receivable inthe neck portion of the opening 11. Suitable O-type sealing rings 14 and15 are disposed about the plug 13 to insure a pressure tight sealbetween the neck of the flask and the housing structure.

The upper end of the housing structure 12 includes a cap 16, preferablyof plastic material, through which extends a stirring means in the formof a rod 17 terminat ing at its upper exterior end in a suitablerotating means such as a motor 18. The lower end of the stirring rod 17extends within the flask 10 as shown and terminates in a lateralstructure such as a propeller 19 to effect mixing of the contents of theflask upon rotation of the rod.

Referring now to FIGURE 2, details of the packing gland structure withinthe housing 12 will be evident. As shown, the cap 16 is threaded intothe upper end of the housing 12 as at 20 and includes a sealing O-ring21 to define within the housing an inner chamber 22.

The housing and cap structure are provided with inlet and outlet bores23 and 24 having first ends extending into the chamber 22 and secondends communicating respectively with the interior of the flask 10 andthe exterior thereof. It will be noted that the stirring rod 17 is oflesser diameter than these bores.

The first end of the inlet bore 23 terminating within the chamber 22 isdesignated 25' and includes an annular Teflon insert 26. A firstresilient sleeve 27, preferably formed of surgical type rubber,surrounds bore 28 at one end and has its other end extending for a givendistance axially along the rod 17 and thence surrounding the peripheryof the rod in sealing engagement therewith as indicated at 29.

Similarly, the first end of the second bore 24 in the cap structure 16is indicated at 30' extending into the chamber 22 and is provided with aTeflon insert 31 and resilient sleeve 32. This sleeve surrounds the boreand extends axially along a portion of the rod 17 in opposedrelationship to the sleeve 27 and thence engages about the rod 17 insealing relationship. The bore ends, Teflon inserts, and resilientsleeves are entirely symmetrical as described, but are disposed inopposing relationship within the chamber 22. The Teflon inserts preventwhipping movements of the rod 17 when rotated at high speeds.

FIGURE 3 illustrates in greater detail the first end 25 of the bore 23together with the Teflon insert structure 26 and sleeve 27. Since thediameter of the stirring rod 17 is less than the inlet bore 23, theinterior of the sleeve 3 27 will be subject to the interior pressure ofthe flask This pressure is designated P1 in FIGURES 1, 2, and 3.

Similarly, with reference again to FIGURE 2, the interior of the secondresilient sleeve 32 will be subject to the exterior pressure designatedP2. The inner chamber 22 is filled with an incompressible fluid such aslubricating oil designated by the arrow 33. The exterior of the sleeves27 and 32 are thus subject to the pressure of this incompressible fluid.

In operation, assume first that the pressure P1 in the flask 10 isconsiderably less than the exterior pressure P2 outside of the flask andhousing. Such a condition would obtain if the ingredients being mixed inthe flask were under high vacuum. In this case, the incompressibleliquid 33 in the chamber 22 will be subject to the exterior pressure P2since this pressure is communicated to the fluid through the enlargedoutlet bore 24 and the resilient nature of the sealing sleeve 32. Theinterior of the first sleeve 27 on the other hand is at a greatlyreduced pressure corresponding to the pressure P1 in the flask.Therefore the greater exterior pressure will be communicated by thefluid 33 to compress the annular sleeve 27 into tight sealingrelationship with the stirring rod 17. The greater the pressuredifferential, the greater will be the pressure exerted on the sleeve.The rod 17 may be rotated at a high speed and the seal maintained, theincompressible fluid in the form of a lubricating oil serving tolubricate the engaging interior surfaces of the sleeve with the rodportion passing therethrough.

It now the presure P1 within the enclosure or flask 10 should be greaterthan the ambient pressure P2, this increased pressure within theenclosure will be communicated to the incompressible fluid 33 in thechamber 22. The manner in which this takes place will be evident inFIGURE 3 wherein, when the pressure P1 is greater than the ambientpressure, there will be a tendency for the sleeve 27 to bow outwardly asindicated by the dotted lines 27. Since the fluid within the chamber isincompressible, this increased pressure is communicated through thefluid to the second sleeve 32 of FIGURE 2 thereby causing it to engagemore tightly the rod 17 in sealing relationship. The contents of theenclosure may thus be stirred while maintaining the pressure within theenclosure.

It should be noted with respect to the foregoing that the axial distancethe sleeve extend along portions of the stirring rod 17 is suificient toallow resilient movement of the mid-portions of the sleeves so thatpressure differences may be communicated by the fluid between therespective sleeves without the engaging end portions of the sleevesleaving the rod 17. Thus, there is not any possibility of contaminationof the fluid 33 in the chamber by the contents within the enclosureregardless of whether the pressure in the enclosure is greater or lessthan the ambient pressure.

From the foregoing description, it will thus be evident that the presentinvention has provided a greatly improved packing gland particularlysuitable for use with flasks and the like to enable the contents thereofto be stirred and yet maintain the pressure within the flask as wouldexist were the flask completely hermetically sealed.

While the invention has been described in conjunction with chemicalflasks and the like, it will be evident that the packing gland structuremay be used to maintain a pressure within any suitable enclosure intowhich a mechanism extends for stirring the contents of the enclosure orotherwise treating the same. The packing gland is therefore not to bethough of as limited to the exact application or structure set forth.

What is claimed is: v

1. A packing gland for passing a rotatable member into an enclosurehaving a pressure different from the exterior pressure comprising: ahousing defining an inner chamber and having inlet and outlet borescommunicating at first ends with said chamber and at second ends withsaid enclosure and the exterior thereof respectively, said rotatablemember passing from the exterior through said bores into said enclosure;and first and second resilient seals in said chamber surrounding saidfirst ends of said bores and portions of said rotatable member inopposing relationship, said inner chamber incorporating anincompressible fluid and confining the same to a substantially fixedvolume and provided with a pressure corresponding to the greater of thetwo pressures defined by the pressure in said enclosure and the exteriorpressure, whereby that resilient seal subject to a greater externalpressure than internal pressure is held by said fluid in hermeticallysealing relationship to said rotatable member.

2. A packing gland for passing a stirring means into an enclosure havinga pressure less than the exterior pressure for stirring the contents ofsaid enclosure while maintaining the pressure in said enclosure at itslesser value, including: a housing defining an inlet bore extending fromsaid enclosure at a first end and communicating with the interior ofsaid enclosure at its second end, said stirring means passing throughsaid inlet bore into said enclosure from the exterior and being ofsmaller diameter than said bore; and a resilient sleeve surrounding thefirst end of said inlet bore and extending axially along a portion ofsaid stirring means extending from said inlet bore a given distance andthence engaging the periphery of said portion to provide an hermeticalseal thereabout, said housing having an inner chamber incorporating anincompressible fluid and confining the same to a substantially fixedvolume and provided with a pressure greater than said interior pressurein said enclosure, whereby the interior of said sleeve is subject to thelesser interior pressure in said enclosure and the exterior of saidsleeve is subject to the pressure of said fluid to hold said sleeve inhermetically sealed relationship with said stirring means.

3. A packing gland for passing a stirring means into an enclosure havinga pressure greater than the exterior pressure for stirring the contentsof said enclosure while maintaining the pressure in said enclosure atits greater value, including: a housing defining an inner chamber inpressure communication with said enclosure having an outlet borecommunicating with said chamber at a first end and extending from saidchamber at its second end, said stirring means passing through saidoutlet bore into said chamber and said enclosure from the exterior andbeing of smaller diameter than said bore; and a resilient sleevesurrounding the first end of said outlet bore and extending axiallyalong a portion of said stirring means extending into said chamber agiven distance and thence engaging the periphery of said portion toprovide an hermetic seal thereabout, said housing having an innerchamber incorporating an incompressible fluid and confining the same toa substantially fixed volume and provided with a pressure at least equalto said interior pressure in said enclosure, whereby the interior ofsaid sleeve is subject to said exterior pressure and the exterior ofsaid sleeve is subject to the pressure of said fluid to hold said sleevein hermetically sealed relationship with said stirring means.

4. A packing gland for passing a stirring means into an enclosure havinga pressure different from the exterior pressure for stirring thecontents of said enclosure while maintaining the pressure in saidenclosure, comprising, in combination: a housing defining an innerchamber and having inlet and outlet bores passing into said chamber atfirst ends and communicating with the interior of said enclosure and theexterior thereof at second ends respectively, said stirring meanspassing through said bores into said enclosure from the exterior andbeing of smaller diameter than said bores; and first and secondresilient sleeves surrounding said first ends of said inlet and outletbores respectively and extending axially along the portions of saidstirring means extending from said bores into said chamber for a givendistance and thence engaging the periphery of said portions to providehermetic seals thereabout; said inner chamber incorporating anincompressible fluid and confining the same to a substantially fixedvolume for communicating the pressure to which the interior of saidfirst sleeve is subject to the exterior of said second sleeve when theinterior pressure in said enclosure is greater than the exteriorpressure; and communicating the pressure to which the interior of saidsecond sleeve is subject to the exterior of said first sleeve when theexterior pressure is greater than the interior pressure in saidenclosure.

5. A packing gland according to claim 4, in which said first and secondbores are in axial alignment and said stirring means includes anelongated straight rod of circular cross-section adapted to have itsexterior end rotated and terminating at its interior end in saidenclosure in laterally extending mixing means.

6. A packing gland according to claim 5, in which said incompressiblefluid comprises a lubricating oil.

5 References Cited UNITED STATES PATENTS 571,741 11/1896 Bates 277-59654,882 7/ 1900 Durand et al 277-59 10 2,731,282 1/1956 McManus et al.277-59 FOREIGN PATENTS 858,483 12/ 1952 Germany. 333,339 8/1930 GreatBritain.

1 LAVERNE D. GEIGER, Primary Examiner.

D. MASSENBERG, Assistant Examiner.

1. A PACKING GLAND FOR PASSING A ROTATABLE MEMBER INTO AN ENCLOSUREHAVING A PRESSURE DIFFERENT FROM THE EXTERIOR PRESSURE COMPRISING: AHOUSING DEFINING AN INNER CHAMBER AND HAVING INLET AND OUTLET BORESCOMMUNICATING AT FIRST ENDS WITH SAID CHAMBER AND AT SECOND ENDS WITHSAID ENCLOSURE AND THE EXTERIOR THEREOF RESPECTIVELY, SAID ROTATABLEMEMBER PASSING FROM THE EXTERIOR THROUGH SAID BORES INTO SAID ENCLOSURE;AND FIRST AND SECOND RESILIENT SEALS IN SAID CHAMBER SURROUNDING SAIDFIRST ENDS OF SAID BORES AND PORTIONS OF SAID ROTATABLE MEMBER INOPPOSING RELATIONSHIP, SAID INNER CHAMBER INCORPORTING AN INCOMPRESSIBLEFLUID AND CONFINING THE SAME TO A SUBSTANTIALLY FIXED VOLUME ANDPROVIDED WITH A PRESSURE CORRESPONDING TO THE GREATER OF THE TWOPRESSURES DEFINED BY THE PRESSURE IN SAID ENCLOSURE AND THE EXTERIORPRESSURE, WHEREBY THAT RESILIENT SEAL SUBJECT TO A GREATER EXTERNALPRESSURE THAN INTERNAL PRESSURE IS HELD BY SAID FLUID IN HERMETICALLYSEALING RELATIONSHIP TO SAID ROTATABLE MEMBER.